FIG 3.

Analysis of PG precursor pools in Nonomuraea sp. ATCC 39727 and its derivatives. The Nonomuraea sp. strains listed in Table 1 were grown for 72 h in VSP medium. The wild-type strain was grown in the absence and presence of 50 μg/ml penicillin G. Cytoplasmic PG precursors were extracted from exponentially growing cultures treated with bacitracin and analyzed by HPLC-MS/MS. The relative abundances (%) of UDP-MurNAc-pentapeptide (black bar) and UDP-MurNAc-tetrapeptide (gray bar) were calculated by the integration of absorbance at 262 nm (mean value from a minimum of three independent cultures). In the Nonomuraea sp. strain carrying pST30 and expressing vanH_atA_atX_a from A. teichomyceticus, the UDP-MurNAc-pentadepsipeptide terminated in d-Lac (cross-hatched bar).